1. Field of the Invention
The invention relates in general to television receiving systems, and in particular, to an analog TV receiving system with a digitized analog TV demodulator.
2. Description of the Related Art
A television (TV) includes a television receiver to receive terrestrial broadcast, cable or satellite broadcast television signals and to process the television signals into appropriate video signals for display and audio signals for hearing. Television signals are transmitted in analog or digital formats and in accordance with a variety of standards. The NTSC (National Television Standards Committee) standard, the PAL (Phase Alternate Lines) standard, and the SECAM (Sequential Couleur Avec Memoire) standard are widely adopted for analog TVs, and the DVB (Digital Video Broadcast) format and the ATSC (Advanced Television Standards Committee) standards are employed for digital TVs. Because different television formats and standards are incompatible with one another, television receivers are traditionally made specifically for the analog or digital format and for a specific standard. Television receivers are dedicated to being used in the geographic region in which the television standard is being broadcasted.
Conventional television receivers, for both analog and digital TVs, receive an incoming television signal in radio frequency (RF) and convert the RF to an intermediate frequency (IF) signal by using an IF downconverter. The IF signal is filtered, amplified, and demodulated by a predetermined television signal format and standard. For analog television signals, the demodulator used is a VIF/SIF module, providing a video output such as a CVBS (Composite Video Baseband Signal) and an audio output such as an MPX or A2. For digital television signals, the demodulator employs an analog-to-digital converter and other supporting circuitry to perform demodulation to output display and audio information to a digital TV.